JP2571361B2 - Shifting method by automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shift method using an automatic transmission that automatically switches a gear train of a transmission to a shift speed determined based on vehicle information.

2. Description of the Related Art There is known an automatic transmission (disclosed in the specification and drawings of Japanese Patent Application No. 59-50747) for automatically switching a gear position of a transmission in a power transmission system of a vehicle. This automatic transmission controls a clutch, a transmission, and a fuel supply amount adjusting device in accordance with control programs for starting, starting, and shifting of a built-in vehicle in advance based on vehicle information.

In particular, at the time of gear shifting, the automatic gear shift controller of the automatic transmission first sets the gear position specified by the gear shift switch or the optimum gear position determined based on the vehicle information using the gear position selection map as the shift target gear position. decide. Then, the automatic transmission controller performs, for example, shift-down control as shown in FIG. 5 in order to automatically shift the gear position to the target gear position. In this case, the automatic transmission controller first disengages the clutch at time T1 (the clutch stroke Sc and the corresponding clutch air pressure Pa increase), and thereafter holds the engine speed Ne, during which the gear shift unit is operated. Activate to increase the clutch output shaft speed Ncl to a value corresponding to the vehicle speed. That is, in order to adjust the gear position to the target gear, first, the gear position is temporarily returned to the neutral line, and the gear train of the target gear is immediately meshed. At this time, it takes time for the Ncl pull-up area F1 that the rotation on the counter shaft side is raised by the action of the synchronization mechanism to match the rotation on the main shaft side of the transmission, and the engine rotation in the subsequent half clutch area F2 An operation of gradually increasing the number Ne and adjusting the number Ne to the clutch output shaft rotation speed Ncl is performed. After a time T3 at which the two rotations are regarded as coincident, the clutch is completely engaged, and the downshift control ends.

(Problems to be Solved by the Invention) As described above, in the conventional shifting method, the pull-up range F1 of the clutch output shaft rotation speed Ncl is relatively long, and the subsequent half-clutch operation range F2 also requires considerable time. .

Thus, in the conventional shifting method, the shift-down time TA from clutch disengagement to clutch engagement, which is the time required for shifting, is relatively long, and it is desired to reduce this.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shift method using an automatic transmission that can reduce a shift down time as compared with the related art.

(Means for Solving the Problems) In order to achieve the above object, the method of the present invention comprises a clutch control means for connecting and disconnecting a clutch between an engine and a transmission of a vehicle, and a method for controlling rotation of the engine. Fuel supply amount adjusting means, a gear position switching means for switching the gear position of the transmission to a target gear position to be shifted, and an automatic control for controlling the clutch control means, the fuel supply amount adjusting means and the gear position switching means at the time of gear shifting. Only when the target shift speed is lower than the specified shift speed and the shift speed is equal to or higher than the specified vehicle speed set for each shift speed using the shift controller, the clutch output during the previous clutch engagement operation is performed. It is characterized in that the shaft rotation is raised to a predetermined value, and an operation of adjusting the gear position to the target shift speed is performed at the time of a subsequent clutch engagement operation.

(Operation) In the method of the present invention, when the downshift is performed, the target shift speed is lower than the specified shift speed, and when the current vehicle speed is equal to or higher than the specified vehicle speed set for each shift speed, the synchro work amount is changed. When it is large, under this double clutch operating condition,
The rotation of the clutch output shaft is raised during the previous clutch connection / disconnection operation, the gear position is adjusted to the target gear position during the subsequent clutch connection / disconnection operation, and then the rotation of the clutch output shaft connected to the axle side and the engine Join the clutch together with the rotation. Therefore, the double clutch operation is performed only under the condition that the synchro work is large, and the rotation of the clutch output shaft is increased when the clutch output shaft is performed alone, or the clutch output shaft and the engine are connected to the axle side. The time required for the rotation alignment with the above is short in each case.

(Embodiment) FIG. 1 shows an example of an automatic transmission used in a shift method by the automatic transmission to which the present invention is applied.

The automatic transmission can start, start, and shift-control a vehicle equipped with a diesel engine (hereinafter simply referred to as an engine) 1. The engine 1 is equipped with an electronic gahana controller 2 as a fuel supply adjusting device and a fuel injection pump 3 operated by the electronic gahana controller 2. The fuel injection pump 3 is mounted on a rack 30 by an electromagnetic actuator 4 which operates according to an operation signal from the electronic governor controller 2.
1 is operated and fuel is adjusted. A transmission 7 having a dry friction clutch (hereinafter simply referred to as a clutch) 5 and a gear shift unit 6 is sequentially connected to the engine 1.

The clutch 5 includes a clutch control means for continuously changing the connection / disconnection state. The clutch control means includes an air cylinder 8 as a clutch actuator and a clutch air system. The clutch air system supplies and discharges air from the air tank 11 to the air cylinder 8 using two solenoid valves 9 and 10.
That is, when the clutch is disengaged, the normally open solenoid valve 9 is turned on and closed, and the normally closed solenoid valve 10 is turned on and opened. When the clutch is gradually returned in the joining direction, the solenoid valve 10 is turned off and closed, and the solenoid valve 9 is operated at a predetermined duty ratio.

A gear shift unit 6 as a gear position switching means of a transmission has a plurality of (only one is shown in FIG. 1) electromagnetic valves 12 and a power cylinder (see FIG. 1) through which high-pressure air from an air tank 11 is supplied and discharged by the valves. (Not shown)), whereby the meshing mode of the gear train of the transmission can be switched. The gear shift unit 6 is provided with a gear position sensor 13 for detecting a gear position.

The electronic governor controller 2 is an automatic transmission controller 14
A drive signal of an appropriate level is output to the electromagnetic actuator 4 based on a voltage value as a load signal from the electromagnetic actuator 4.

The automatic transmission controller 14 and the electronic governor controller 2 are both composed of microcomputers. In particular, the automatic transmission controller 14 receives a shift signal for each range shown in FIG. An accelerator opening signal is input. Moreover,
Engine rotation sensor 17 that outputs engine rotation speed, clutch rotation sensor 1 that outputs rotation speed of clutch output shaft 18
9. A vehicle speed sensor 20 for outputting a vehicle speed signal, an exhaust switch 21, and a service brake switch 22 are also connected.

3 and 7 are stored in the memory of the automatic transmission controller 14.
In addition to the control programs shown in FIGS. 8A, 8B, 8C, and 8, a data table (not shown) for obtaining a duty ratio corresponding to the accelerator opening used when operating the clutch, An output data table (not shown) of an operation signal to the electromagnetic valve 12 of the gear shift unit corresponding to the signal, a plurality of data tables (not shown) for selecting a shift speed based on the vehicle speed and the accelerator opening, and other regulations The values and the like are stored and processed.

Using such an automatic transmission shown in FIG. 1,
The case of implementing the method of the present invention will be described together with the control program of the automatic transmission controller 14. In addition, the code | symbol C in FIG. 3, the code | symbol D in FIG. 7, and the code | symbol E in FIG. 8 show a control step, respectively.

In the main routine of FIG. 3, when the control program starts, an engine start process is performed based on inspection of each part, reading of an input signal, and other preprocessing (step 1). After starting the engine, it is determined in step 2 whether the vehicle stops or runs when the vehicle speed is equal to or less than a specified value (for example, 2 to 3 km / h). If the vehicle is stopped, the process proceeds to step 3, and if the vehicle is running, the process proceeds to step 4.

In the start process, first, an operation signal is output to both solenoid valves 9 and 10, the clutch is disengaged, the gear position of the transmission is switched to the start position, and when the accelerator opening exceeds a specified value, the clutch is moved in the joining direction. The engine is gradually returned, and the rotation of the engine output shaft and the rotation of the clutch output shaft are gradually brought close to each other.

On the other hand, when the vehicle is traveling, the routine proceeds to step 4, where a gear shifting process is performed. This gear shifting subroutine is shown in FIGS. 7 and 8. The method of the present invention is executed during this shift processing.

In the speed change process shown in FIG. 7 (a), first, in step 1, a brake failure is determined based on a check of the air pressure and the like. And proceed to step 2 with No. In step 2, based on the shift signal, an automatic selection shift range such as Pw (selects a shift position based on a shift position selection map emphasizing acceleration) or D (changes a gear position based on a shift selection map emphasizing economy) is set. Select), the process proceeds to step 3 in the designated gear range, to step 4 in FIG. 7B, to the step 5 in FIG. 7C in the reverse range, and to step 6 if neither. .

In step 3, it is determined whether or not the exhaust is in use. When not in use, in step 7, a general gear position selection map is selected.
When the vehicle is in use and the service brake is on, the process proceeds from step 8 to step 9 to select a shift stage selection map for exhaust and service brake, and when only an exhaust train is selected, a shift stage selection map for exhaust stroke is selected in step 9 (step
Ten). After such a map selection, the process proceeds to step 11 to determine an optimum gear position to be the target gear position based on the vehicle speed and the accelerator opening. If the current gear and the optimal gear are the same, the process proceeds from step 12 to step 13, and if not, the process proceeds to step 14 to determine whether or not an upshift is to be performed. If the shift is up, the current position of the rack 301 is read in step 15, and
In step 16, it is determined whether or not there is still enough driving force to overcome the running resistance even after the upshift. If the running resistance is large, that is, if the upshift is inappropriate, the process proceeds to step 13, and if the upshift is adapted, the process proceeds to step 17 (step 7).
Go to FIG.

Here, if the process proceeds to the No side from step 14, that is, to step 18, if the exhaust is used, the process proceeds to step 17. If the exhaust is not used, it is further determined whether or not the service brake is turned on. It is similar to a gentle downhill because it is on the downshift side)
Step 19 if used (similar to a steep descent)
Go to step 20. Here, if it is a downshift of 5th speed or less, the process proceeds to step 13, and if the clutch is released,
If not, return to step 21. That is, when proceeding from step 20 to step 13, downshifting of the fifth speed or lower is prevented, thereby giving priority to ensuring the operation time of the engine brake.

Proceeding from step 2 to step 4, if the current gear and the designated gear (first to fifth gears) are the same, step 13
Otherwise, go to step 22. Here, it is determined whether or not downshifting from the D range is performed. If YES, the process proceeds to step 23, and if No, the process proceeds to step 17. In step 23, first, it is determined whether or not the vehicle enters the overrun vehicle speed due to downshifting,
If it is overrun, the process proceeds to step 13; otherwise, a pseudo voltage as a pseudo load signal is output to the electronic governor controller to hold the current engine speed Ne. Then, in step 25, the clutch is disengaged, the target gear is determined to be one gear lower than the current gear, and the process proceeds from step 26 to 27,
It is determined whether the downshift is a downshift of the fifth speed or lower. If the fifth speed or higher, the process proceeds to step 28, in which the gear shift unit 6 is operated to switch the gear position to the target shift speed, and the process proceeds to step 21.

When step 17 is reached from step 22, etc., it is determined here whether or not an upshift is to be performed.
The process proceeds to step 30 for downshifting from the designated gear position to 29. In the upshift, the process proceeds to steps 29, 31, and 32, where the engine speed Ne is returned to the idle speed, the clutch is disengaged, and the target shift speed is determined as the designated speed of the change lever. In step 30, it is determined whether or not the engine speed falls within the overrun due to downshift. If not, the process proceeds to step 33, in which a warning lamp (not shown) is turned on to prevent downshift and return. I do. If it does, the process proceeds to step 34, where the engine speed Ne is held as in step 24, and the process proceeds to step 31.

In step 27, if it is a downshift of 5th speed or less, the process proceeds to step 35; otherwise, the process proceeds to step 28. Steps
At 35, calculation is performed according to a characteristic diagram (see FIG. 4) corresponding to a map for setting the prescribed vehicle speeds V1 to V5 at each shift speed. If the current vehicle speed exceeds the prescribed vehicle speed, the double clutch process at step 36 is performed. Otherwise, go to step 28.

Here, as a condition of whether or not to perform the double clutch process, the case where the fifth speed or less is set as the target shift speed and the current vehicle speed exceeds the specified vehicle speed at each shift speed is defined as a case where the shift speed is higher than the fifth speed. This is because the ratio is relatively small, and the synchro work at the time of shifting is also small, and further, the synchro work is small at or below the specified vehicle speed.

That is, in a normal downshift situation where the synchro work is small, a short and smooth shift can be performed, and the downshift time TA as shown in FIG. 5 also becomes short. Therefore, if the double clutch process is performed, the shift-down time TB (see FIG. 6) at that time becomes longer. For this reason, the conditions for performing the double clutch process are set in a downshift situation in which the target shift speed is lower than the specified shift speed and the synchro work amount at or above the specified vehicle speed is large.

In step 35, for example, if the shift down is performed from the third speed to the second speed, the process proceeds to step 36 because the vehicle speed Va is higher than the specified vehicle speed V2 at 2. Conversely, assuming that the vehicle speed is Vb, the process proceeds to step 28 because V2> Vb (see FIG. 4).

Here, a subroutine relating to the double clutch process will be described with reference to FIGS. 8 and 6. FIG.

Here, the clutch has already been disengaged at time T1, and first, in step 1, the target clutch speed after downshifting is calculated and determined from the coefficient α stored in advance based on the current clutch speed. In step 2, if the determined target clutch rotational speed Ncl is larger than a specified value (here, 2300 rpm), the target clutch rotational speed is corrected and re-determined as 2300 rpm. Here, a signal for setting the gear position to neutral is output, and in step 5, it is determined whether the shift to neutral is started, that is, waiting for the gear position signal (SH signal) issued at the current gear position to be cut off, step 6, step Proceed to 7. Then, a clutch engagement signal is output at time T4, and immediately after that, a pseudo voltage is output to increase the engine rotation with the accelerator opening set to 100%. Accordingly, the clutch output shaft (the clutch output shaft 18 is connected to the counter shaft 701 of the transmission at this time,
The rotation speed N of the main shaft 702 side is in a free state)
cl also increases rapidly. Thereafter, in step 8, the control waits until the clutch output shaft rotation speed Ncl reaches the target clutch rotation speed, and then proceeds to step 9, where a voltage corresponding to the clutch output shaft rotation is output.
Then, at a time point T5, the vehicle passes through the clutch complete connection point, and at a time point T6, a subsequent clutch disconnection operation starts (step 10). Subsequently, in step 11, the gear position is switched to the target shift speed, and the routine returns.

When step 21 in FIG. 7B is reached from the double clutch subroutine or the like, the clutch output shaft
The main shaft 701 and the axle side are connected to a counter shaft 701 which is always connected to 18, and outputs a pseudo voltage corresponding to the rotation speed Ncl of the clutch output shaft. After this,
Proceeding to steps 37, 38, and 39, return the clutch to the position immediately before the half clutch (LE point), output a pseudo voltage equivalent to the rotation of the clutch output shaft again, and operate the solenoid valve 9 at a duty ratio according to the accelerator opening. Then, the clutch is maintained in the half-clutch state, and the routine proceeds to step 40. As shown in FIG. 7 (c), here, if the clutch output shaft rotation, that is, the vehicle speed is lower than the specified value, and the vehicle speed further continues to decrease, that is, from steps 40 and 41, to the YES side. When proceeding, the process is switched to the starting process. Conversely, if the vehicle speed does not decrease, the control on the shift processing side is maintained, and the process proceeds from step 41 or from step 40 to 42, where the synchronization point is determined from the difference between the engine speed Ne and the clutch output shaft speed Ncl, and synchronization is performed. If not, step 38
Return to and wait for synchronization. Synchronizing at time T3, steps 43 and 4
Proceed to 4 to engage the clutch and release the pseudo voltage.

When proceeding from step 2 to step 5, that is, when the change lever is switched to the reverse range due to erroneous operation regardless of the specified vehicle speed or more, first, as shown in FIG. 7 (c), the current gear position is reverse. And step 13
If not, then it is determined in step 45 whether or not the gear is neutral, and if the gear position is neutral, the flow proceeds to step 46.
Otherwise, go to step 47. In step 47, the idle pseudo voltage is output, and the process proceeds to steps 48, 49, and 46, in which the clutch is disengaged, the gear position is held on the neutral line, and an erroneous operation is notified by a warning lamp (not shown). Proceed to step 43.

When proceeding from step 2 to step 6, that is, when the change lever is not in any range or in neutral, first, if the lever moves within the specified time t, return to step 2; It is determined whether or not the current gear position is in the neutral stage. If it is neutral, proceed to step 13; otherwise, proceed to steps 51, 52, 53, output the pseudo voltage for idling, disengage the clutch, maintain the gear position on the neutral line, and proceed to step 43.
It will advance to.

(Effects of the Invention) According to the method of the present invention, the current gear position is switched to the target shift speed by performing a double clutch operation at the time of shift down lower than the specified shift speed and at least downshifting the specified vehicle. The clutch output shaft rotation pull-up area F1 and half-clutch area F2 do not become longer as in the past, requiring a very short time, and the downshift time TB (see Fig. 6) is the conventional value.
Shorter than TA. According to actual measurement, data of 1.8 seconds of TB value was obtained for 2.4 seconds of TA value. As a result, the downshift can be performed quickly, and the loss of the engine brake operating time due to the shift is reduced.
By performing the double clutch operation at the time of downshifting with a small amount of synchro work, it is possible to prevent the shift time from becoming longer, and to efficiently enjoy the advantages of the double clutch operation.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an automatic transmission used for executing the method of the present invention, FIG. 2 is a shift pattern diagram of a transmission of the same device, FIGS. 3, 7 (a), (b), ( c), FIG. 8 is a flowchart of a control program incorporated in the above-mentioned device, and also shows steps of the method of the present invention. FIG. 4 is a diagram showing a vehicle speed-engine speed diagram at the time of downshifting performed by the above-mentioned device. , FIG. 5 is a time-dependent explanatory diagram of the conventional downshift, and FIG. 6 is a time-dependent explanatory diagram of the downshift by the method of the present invention. 1 ... Engine, 2 ... Electronic governor controller, 4 ...
... Electromagnetic actuator, 5 ... Clutch, 6 ... Gear shift unit, 7 ... Transmission, 8 ... Air cylinder, 9,
10 ... Solenoid valve, 14 ... Automatic transmission controller.

Continued on the front page (72) Inventor Shiki Fukushima 4-2-1-1, Shimomaruko, Ota-ku, Tokyo Mitsubishi Motors Corporation Tokyo Motor Works Maruko Plant

Claims (1)

(57) [Claims] 1. A clutch control means for connecting and disconnecting a clutch between an engine and a transmission of a vehicle, a fuel supply amount adjusting means for operating rotation of the engine, and a gear position of the transmission to be shifted. A gear position switching means for switching to a target gear, and an automatic transmission controller for controlling the clutch control means, the fuel supply amount adjusting means and the gear position switching means at the time of gear shifting, wherein the target gear is lower than a specified gear; The clutch output shaft rotation is raised to a predetermined value at the time of the previous clutch connection / disconnection operation only at the time of shift down at a speed equal to or higher than the specified vehicle speed set for each gear stage and at the time of subsequent clutch connection / disconnection operation. And performing an operation for adjusting a gear position to a target shift speed.